Explosive gate,diode and switch



March 4, 1969 D. A. SILVIA ET AL 3,430,564

, EXPLOSIVE GATE, DIODE AND SWITCH Filed May :3, 1967 Sheet of z FIG. 1FIG. 2 20' INVENTORS Den/s A. .Si/w'a Richard 7. Ramsey John H. encer BYM f nrronun W M4 our March 4, 1969 D. A. SILVIA ETAL 3,430,564

EXPLOSIVE GATE, DIODE AND SWITCH Filed May a, 1967 Sheet 2 of 2 L FIG. 66

70 MISS ILE SEPARA T/O/V 1' -MI I OUT PUTS 7'0 DEPLOYMENT CHARGES UnitedStates Patent 6 Claims ABSTRACT OF THE DISCLOSURE An improved, allsecondary explosive, logic andswitching device in which a point contactfrom an explosive trail with a constricted region of the same or otherexplosive trail can produce a destructive cross-over, an explosive d1-ode switch or other logic operation.

Government interest in the invention The invention described herein maybe manufactured and used by or for the Government of the United Statesof America for governmental purposes without the payment of anyroyalties thereon or therefor.

Cross-reference to related application This application is animprovement over pending application Ser. No. 478,676, filed June 30,1965, now US. Patent No. 3,289,106 for Explosive Circuits, by Denis A.Silvia.

Background of the invention In the above referred to patent application,explosive circuit elements are disclosed, including the destructivecrossover and the null gate, from which all the primary functions ofbinary logic can be constructed. The destructive crossover is formed byproviding a pair of trails on the surface of an inert material whichtrails intersect at right angles and are filled with an explosive. Gapsare left at the intersection to provide a junction or island, such that,propagation through the leg of one trail, is strong enough to jump itsgap and consume the explosive in the island, thereby preventingpropagation from one to the other leg of the intersecting trail. Thedetonation proceeding along either trail is not strong enough, however,to turn the corner into either leg of the perpendicular trail. The nullgate and other binary logic functions are constructecl as extensions ofthe basic destructive crossover. Although this system is workable andunlocks a new scope to explosive circuitry, dimensions of the trails andgaps are extremely critical and do not lend themselves readily to easymanufacture. The reliability of this system also remains in doubt due tothese factors.

Summary of the invention The instant invention is concerned primarilywith an improved explosive circuit and, in particular, with an explosivediode and an explosive nulling gate from which an integrated circuit canbe constructed paralleling their electronic counterparts. Thecriticality of the trails and gaps as above-noted, has beensubstantially avoided since this invention involves the use of no gaps.The present improvement instead provides for a trail having a neckeddown or notched portion along its length and an intersecting trailterminating at a point and making a point contact with the notched area.Consumption of the explosive at the notch via the point contact preventsfurther propagation along the other trail. In like manner, an explosivediode is constructed wherein a single explosive trail is provided with aconstricted area along one portion of its length and a point alonganother portion of its length "ice making a point contact with theconstriction. Propagation in only one direction thereby results if theexplosive is made to pass in a direction reaching the constricted areafirst. Propagation, therefore, continues to the end of the trailuninterrupted. However, if the direction of the explosive is such thatthe point is first reached, the constriction is consumed and furtherpropagation through the trail is prevented. The nulling gate easilygives rise to the construction of an explosive switch and together withthe explosive diode an explosive circuit may be provided. One suchcircuit contemplated uses merely two explosive inputs and yields five ormore explosive outputs. Primary explosive is required only at theexplosive inputs whereas secondary explosive is sufficient for-thecircuitry itself, thereby requiring only two safe arming devices insteadof five.

Brief description of the drawings FIG. 1 illustrates an explosive nullgate according to the instant invention;

FIG. 2 illustrates an explosive diode according to the presentinvention;

FIG. 3 is the same diode as in FIG. 2 except that a more streamlinedversion is shown;

FIG. 4 is an elementary circuit involving two gates used to construct anexplosive switch;

FIG. 5 illustrates a destructive crossover constructed from twoexplosive diodes and two explosive gates;

FIG. 6 is an explosive circuit according to the present inventionillustrating the construction of five outputs from two sequenced inputs;and

FIG. 7 is an explosive circuit using the outputs from FIG. 6 forperforming the firing operation of a specific warhead design.

Description of the preferred embodiments The explosive circuitryaccording to the afore-described related design is a sufficientlyreliable system if extreme care is taken to construct the critical traildimensions and gap spacings. In the interest of expediting productionmanufacture of miniature charges and in improving upon reliability, theends of the trails in the related application were first sculpted toform miniature shaped charges. This modification significantly improvedits reliability and largely eliminated crosstalk between intersectinglegs of the null gate. A bonus was obtained in that the gate wouldpropagate only in the direction of the shaped charge since such a chargeis inherently unidirectional. Removal of the incoming trail from thegate and the junction between trails produced a diode since the gapcould be crossed only in the forward direction of the shaped charge.This system was found to work quite reliably but the gap dimensions werestill somewhat critical and the fabrication tedious. Need forelimination of the critical gap led to the instant invention of whichFIG. 1 illustrates a plate 10 of inert material with an explosive trailB and an explosive trail A provided thereon. These trails may beconstructed by forming a channel or grooves in plate 10 and filling themwith an explosive, such as Du Pont EL506C, or, by fabricating the trailsusing the Du Pont sheet explosive. The null gate of FIG. 1 is a simpleexplosive switch which performs the function of disrupting an explosivetrail.

. The null gate can be used to form an explosive diode as well as otherexplosive elements such as the selective switch, all of which will behereinafter described.

In FIG. 1, if a detonation proceeds along explosive trail B in eitherdirection, it will normally pass through the constricted region 12,formed by notch 11, and emerge out the other side of the trail. If,however, a detonation on trail A arrives at the constricted area 12 byapproximately one microsecond before the detonation on trail B passestherethrough, then the constriction at 12 is destroyed or consumed andfurther detonation on trail B will be prevented. As can be seen from thedrawings, the trail A terminates at a point 13 and is designed to make aloose contact with the explosive trail B. In this manner, only theexplosive at 12 is destroyed without the remainder of trail B beingaffected. The success of the operation depends on the combined effect ofseveral factors. For example, the explosive width at constriction 12must be less than the minimum thickness for sustained detonation. Thus,the detonation is dying while passing through 12. The length of area 12must also be short enough that sustained detonation is rapidly recoveredafter passing therethrough. Because the detonation is dying in 12, it isthereby easily stopped by breaking from explosive trail A. Also, thenarrowing of trail A as at 13 must be such that it induces a dyingdetonation in the trail, and a destruction at the restricted area 12. Inaddition, the loose contact with area 12 at point 13 makes transfer ofdetonation from A to B more difiicult. As a result, the destruction ofarea 12 is efiected from the sides 14 of trail A, directly blasting in adispersing manner away from point 13 to fully destroy the explosive atthe constricted area. Finally, by notching the side of trail B at 11,directly opposite from trail A, a minimum amount of explosive trail B isexposed to blast from trail A. Since all of these factors supplementeach other, considerable slack is allowable in any one of them leavingreliable operation of the device still capable of being achieved.

In FIG. 2 of the drawings, a plate 20 of inert material is provided withan explosive trail C, D, E, F, G on its surface in the same manner asthe explosive trails on plate 10. An explosive diode is constructed inaccordance with the null gate of FIG. 1 in such a way that it willpropagate detonation in only one direction as shown by the arrow. A moresophisticated and more compact approach to the construction of anexplosive diode is shown in FIG. 3. It is the same in all other respectsto the FIG. 2 diode. In FIG. 3, a plate 30 of inert material is providedon its surface with an explosive trail C, C, E, F, G in theconfiguration shown and constructed according to the manner suggestedwith regard to trails A and B of FIG. 1. As shown in FIGS. 2 and 3, anexplosive diode is constructed which is a one-piece, all secondaryexplosive, significantly smaller and easier to make diode, simply byusing a self-gating explosive trail. A detonation proceeding along thetrail from G to C in FIG. 2 or from G to C in FIG. 3, encounters nodifficulty in being transmitted. On the other hand, when a detonationcommences from C, FIG. 2, or C, FIG. 3, circumstances are entirelydifferent. In FIG. 2, the detonation from C splits into two parts. Onepart trying to take the long path through E while the other takes theshort path through D. Since the path through D arrives at theconstriction 12 first, it destroys the constriction and prevents thedetonation, by way of E, from ever reaching F or G. The diode in FIG. 3operates in a like manner, i.e., a split of the detonation from C intotwo parts; one part trying to take the long path through E while theother takes the short path through D. Since the path through D arrivesfirst at the constriction 12 through point 13, it destroys theconstriction and prevents the detonation by way of E from ever reachingF or G. The arrow in FIG. 3 shows the direction of allowable propagationthrough the diode.

By using two null gates in accordance with FIG. 1, a selective switchcan be constructed as shown in FIG. 4. The trails are constructed oninert plate 40 according to the manner hereinbefore described, and inthe configuration as shown. If detonation occurs on trail A, beforedetonation occurs on trail B, trail A-B will be cut-ofi by the null gateat 41 and the detonation will propagate along A-B to the output. If,however, detonation occurs on trail B before detonation on trail A, thentrail A-E will be cut at the null gate 42 and detonation will thenpropagate on trail A-B since the null gate 41 cannot prevent propagationtherealong.

In FIG. 5, a pair of explosive diodes and a pair of explosive null gatesare used to construct a destructive crossover. A plate 50 of inertmaterial is provided with trails between H and H and between I and Tconfigured as shown and constructed according to the hereinaboveteachings. Propagation commencing at H is transmitted through diode 51after which it splits into three paths; one toward H another toward Kand a third toward L. The path to K subsequently splits into two parts;one toward the null gate 53, the other toward diode 52. The diode at 52prevents further detonation therethrough. The null gate at 53 fails toprevent propagation toward H since the explosive has already passedtherethrough. Propagation through L, on the other hand, arrives at nullgate 54 subsequent to propagation through M whereby continuedtransmission through gate 54 is thereby prevented. Uninterruptedtransmission of the explosive from H to H is accordingly provided.Propagation commencing at I is transmitted toward T in a like manner. Asit passes through diode 52, it is split into two parts; one to N, theother to K. N activates null gate 53 such that K, in subsequentlysplitting off towards gate 53, is prevented from being transmittedtherethrough. Diode 51 prevents K from continuing its propagation t H soK continues on toward L which passes uninterrupted through null gate 54and to T Obviously, M has not been detonated because of N activatingnull gate 53. M therefore fails to activate gate 54 and permits L tocontinue therethrough.

Several applications of explosive circuitry have been considered. Onewhich has received serious attention is the 5 for 2 circuit. In thiscircuit, two inputs are comlined, and, with a subsequent logicalseparation of the signal, through the use of switches, up to fiveseparate outputs are yielded. The circuit is depicted in FIG. 6 in whichfour explosive switches and two explosive diodes are used with delaysregulated by path length. The circuit as given uses the input I only(I), II only (II), I and II, simultaneously (I, II), I followed by II (III) and II followed by I (II I). More outputs could be provided by usingmore than one delay time between I and II for the I II and II I options,thus using two additional switches and delay elements and providing twomore outputs. The circuit herein giving five outputs from two inputsuses the FIG. 3 type diodes and the FIG. 4 type switches describedhereinabove. The explosive circuit of FIG. 6 is printed onto a plate 60of inert material in the same manner as in the above-described figuresand in the configuration as shown by the drawing. Initiation of either Ior II will start detonation on T but the diodes 65, 66 prevent backdetonation toward I or II, respectively.

Upon detonation of I, switch 61 causes detonation to continue along Tbecause of the time delay at D Switches '63 and 64 will allowpropagation therethrough to output I since the paths to I, II and I IIare respectively cut-01f by each switch. If II is detonated at the sametime as I, switch 63 will cause the detonation at T to be switched topath T II and through to output I, II. This switching operation isassured because of the time delay of detonation I as it passes through DIf detonation on II is subsequent to I; II will not arrive at switch 63before detonation on T Detonation on T will continue therethrough, willbe delayed at D; and be switched to output I II by switch 64. Since thedetonation on T; arrives at switch '64 subsequent to the detonation onII due to the time delay at D propagation to output I is switched tooutput I II. If II is detonated first, unaccompanied by I, then thedetonation at T will go through switch 61, to T after which switch 62will cut-01f propagation to output II I and cause it to be switched tooutput II. If I is detonated subsequent to II, the detonation along Iwill reach switch 62 before the detonation along T because of the delayat D Such being the case, propagation to II will be cut-off whereuponswitch 62 will cause propagation to continue toward output II I. Inorder to achieve the five outputs from the above-described explosivecircuit, a simple variability in the functioning time of the detonatorsI, II must be made in the circuit. The delay time for detonation by anelectric cap can be stated as die, where d is the average time and e isthe maximum variation from average time of detonation. The circuitcorrection to take this into account is to place a small delay in trailT, as at D This delay should be of duration 2e. It then easily followsthat D and D must be several times larger than 22 for properfunctioning. For example, e being approximately one microsecond, is notdifficult to obtain from a hot wire cap and, in this case, B; equals Dequals ten microseconds would be an acceptable delay for operation ofthis circuit. The 5 for 2" circuit is then completed and may be usedwith two detonators to provide the equivalent of five detonators if amethod of timing the two inputs is available.

The copending application Ser. No. 643,298, filed May 25, 1967, byAdams, may find specific application of the FIG. 6 type explosivecircuit. There, a four sector warhead device can be explosively openedin such a way that it may be directed in any one of four directions, ordetonated without opening, it so desired. This is performed by usingfour opening charges and appropriate delays in order to give the sectorstime to deploy before detonating the main charges. Explosive circuits,according to the instant invention, may be used in order to reduce thenumber of delays necessary by first mixing the five inputs gathered fromthe five outputs of FIG. 6, to perform missile separation and delayfunctions. One signal is sent to the delay boosters while another isdecoded to actuate the proper opening charge and deploy the warhead. Oneof the signals may bypass missile separation, the opening circuit andthe deploy delay to give instantaneous isotropic detonation.

For a more complete understanding of this specific operation, referenceto FIG. 7 is made. This circuit is constructed onto a plate 70 of inertmaterial as in the other circuits and configured in the manner as shown.The five outputs from the FIG. 6 circuit become inputs to the FIG. 7explosive circuit. Four of these inputs, when initiated, will deploy oneof four hinge and cutting charges, depending on the position of thetarget. The fifth input, when activated, will bypass the deploymentcharges and detonate the entire warhead in a conventional manner. Forexample, in FIG. 7, the explosive trail at II bypasses missileseparation, the opening circuit or deployment charges, and thedeployment delay, and acts to initiate all four explosive boosterssimultaneously for immediate detonation of the entire warhead.Initiation of I only will cause propagation of the explosive to splitinto two directions; one toward diode 71 and the other toward gate 77.The explosive gate at 77 is thereby closed and propagation through diode71 is permitted until it splits off into two additional directions; onetoward diode 74, the other toward gate 78. Diode 74 prevents furtherpropagation and gate 78 is thereby closed. Propagation continues throughdiode 72 until it spilts off again into two more directions; one towarddiode 75, the other toward gate 79. Diode 75, as in 74, prevents furtherpropagation, and gate 79, as in gate diode 78, is thereby closed.Propagation continues further through diode 73 and is split into threedirec tions; one being toward diode 76 which prevents furtherpropagation, one toward the missile separation delay, and the other tomissile separation to eifect a severance of the warhead from themissile. Propagation continues and is impeded at missile separationdelay in order to give the warhead ample time to separate from themissile before proceeding to deployment of the hinge and cutting charge,which is the second step of the operation. Because explosive gates 79,78 and 77 are closed, nothing will prevent propagation along the trailto deploy its proper hinge and cutting charge at output I. It should benoted that the explosive has been sufiiciently delayed at deploymentdelay while the second step of the explosive circuit is being carriedout. As the explosive continues through deployment delay, it is splitoff toward each of four booster outputs for simultaneously exploding thefour opened segments of the warhead. Should the I II sequenced explosiveinput as in FIG. 6 be initiated in the FIG. 7 circuit, propagation wouldproceed through diode 74 and be later split off into three directions;one toward diode 71, which prevents further propagation, one towarddiode 72 and one toward gate 78, which thereby becomes closed.Propagation continues through diode 72 and is split oif again into threedirections; one toward diode 75, which prevents further propagation, onetoward diode 73 and one toward gate 79, which thereby becomes closed. Aspropagation continues through diode 73, it is again split up in threedirections; one towards diode 76, which prevents further detonation, oneto missile separation, which is the first phase of the warheadoperation, and the third through missile separation delay. Here,propagation is sufficiently impeded before continuing through to deploythe hinge and cutting charge. As can be seen, gates 79, 78 are closed,whereby no interference arises in deploying the proper hinge and cuttingcharge at output I II. Also, gate 80 prevents propagation toward outputI. Upon initiation of the I, II input, the explosive is propagatedthrough diode 75 and splits oil in three directions; one toward diode72, which prevents further propagation, one toward explosive gate 79,which thereby becomes closed, and one through diode 73. Athree-direction splitoff is again caused; one toward diode 76, whichprevents further propagation, one to missile separation and one tomissile separation delay for the above-noted reason. Propagation todeploy the proper hinge and cutting charges at output I, II is madepossible by the closing of gate 79. Gate 81 prevents propagation towardoutputs I and I II. Lastly, if it were found necessary to initiate II-I, propagation would proceed through diode 76- and split into threedirections; one toward diode 73, which prevents further propagation,another to missile separation and another to missile separation delay toagain await complete separation of the warhead from the missile. As canbe seen from the drawing, explosive gate 82 prevents propagation towardoutputs I, I II or I, II. In each of the four cases, as the second stepof the operation is completed, f ull deployment is awaited at deploymentdelay. Propagation thereafter continues and splits into four pathstoward the booster outputs for detonating the four open segments of thewarhead simultaneously.

Used throughout the several views of the instant in vention is asecondary explosive for the circuits. Since primary high explosive isnot necessary, no safe arming is needed between it and other parts ofthe explosive trail. For example, in the FIG. 6 explosive circuit onlytwo safe arming devices are required between the inputs at I and II andfive outputs. The use of high explosive only at the two inputseliminates three safe arming devices. As in the FIG. 6 configuration,this is obviously a drastic weight and space saving factor. In addition,the instant invention lends itself to a greater simplicity and ease offabrication of the explosive gate, diode and switch, and, because ofless critical dimensions, reliability of the new devices are muchimproved.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that Within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. An explosive logic device comprising:

a supporting plate of inert material having formed thereon a firstexplosive trail and a second explosive trail, said first trail having aconstricted area along a portion of its length, said second trailterminating at a point and making a loose point contact with said firsttrail constricted area thereby forming an explosive null gate, wherebydetonation proceeding along said first trail in either direction willpass through said first trail constricted area and emerge out the otherside of said first trail if the explosive at said first trailconstricted area has not already been destroyed by a detonationproceeding along said second trail.

2. The device of claim 1 wherein said first trail is notched along saidportion of its length thereby forming said first trail constricted area.

3. The device of claim 2 being further characterized by a thirdexplosive trail and a fourth explosive trail, said third trailcommunicating with said first trail at one side of said first trailconstricted area and said fourth trail communicating with said firsttrail at the opposite side of said first trail constricted area, saidthird trail being notched along a portion of its length thereby forminga third trail constricted area, said fourth trail terminating at a pointand making a loose point contact with said third trail constricted areaand said first and second trails being in communication with each other,thereby forming an explosive switch, whereby detonation proceeding alongsaid first trail will pass through said first trail constricted area andemerge out the other side of said first trail if both the explosive atsaid first trail constricted area has not already been destroyed by adetonation proceeding along said second trail, and, if the explosive atsaid third trail constricted area has been destroyed by a detonationproceeding along said fourth trail.

4. An explosive logic device comprising:

a supporting plate of inert material having formed thereon a continuousexplosive trail having a constricted area along one portion of itslength and an extension forming a point along another portion of itslength, said point forming extension making a loose point contact withsaid continuous trail constricted area thereby forming an explosivediode, whereby detonation in one direction only is allowed along saidcontinuous trail since said continuous trail constricted area will bedestroyed, thereby preventing further propagation, if the detonationarrives first at said point forming extension.

5. The device according to claim 4 wherein said continuous trail isnotched along said first portion of its length thereby forming saidcontinuous trail constricted area.

6. An explosive circuit comprising:

a supporting plate of inert material;

two trails of secondary explosive material formed on said plate forreceiving explosive inputs into the circuit;

two explosive diodes provided between said trails;

at least four explosive switches provided between said trailsinterconnected by paths filled with secondary explosive; and

time delays along said paths, whereby, activation either along one ofsaid trails alone, the other of said trails alone, both of said trailssimultaneously, said one of said trails before said other of saidtrails, or said other of said trails before said one of said trails,will produce at least five explosive outputs.

References Cited UNITED STATES PATENTS 3,095,812 7/1963 Coursen 102-273,175,491 3/1965 Robertson 102-27 3,311,055 3/1967 Stresau et al. 102223,368,485 2/1968 Klotz 102--27 VERLIN R. PENDEGRASS, Primary Examiner.

